Re: Spamassassin+amavis - SpamAssassin

This is a discussion on Re: Spamassassin+amavis - SpamAssassin ; Luis:
2008/10/29 Luis Croker :
>
> How can I tunr off the Network tests (RBLs) ??? Just to probe if it can
> make the delivery faster.
Just to check, you know you should run a RBL check in ...

Re: Spamassassin+amavis

Luis:

2008/10/29 Luis Croker :
>
> How can I tunr off the Network tests (RBLs) ??? Just to probe if it can
> make the delivery faster.

Just to check, you know you should run a RBL check in Postfix BEFORE
it accepts te message, do you? This reduces dramatically the number of
messages your server has to scan. And improves the performance a lot.
Personally, I run Zen, from SpamHaus:

reject_rbl_client zen.spamhaus.org

Try this, so you server doesn't get overloaded with obvious spammy
connections form spambots.
>
>
>
>
> On Wed, 2008-10-29 at 04:05 +0000, Ned Slider wrote:
>
> Gary V wrote:
>>
>> 6 seconds seems somewhat typical. Mostly due to network tests. Some
>> RBLs are no longer and you could turn the non functional RBL rules off
>> by setting to 0. I'm not sure which ones though. Maybe someone else
>> knows.
>>
>
> From my own stats of hits against DNSBLs and URIBLs for the last ~1000
> spam (these results are typical for me):
>
> ## DNSBL Statistics ##
> 1223 RCVD_IN_ZEN (Spamhaus PBL, SBL or XBL)
> 1067 RCVD_IN_UCE_COMBINED (UCEPROTECT level 1, 2 or 3)
> 1052 RCVD_IN_PBL
> 900 RCVD_IN_UCEPROTECT3
> 834 RCVD_IN_UCEPROTECT2
> 678 RCVD_IN_SBLXBL
> 427 RCVD_IN_UCEPROTECT1
> 163 RCVD_IN_PSBL
> 105 RCVD_IN_BL_SPAMCOP_NET
> 15 RCVD_IN_SORBS_WEB
> 14 RCVD_IN_NJABL_PROXY
> 1 RCVD_IN_SORBS_DUL
> 1329 Total Spam
>
> ## URIBL Statistics ##
> 1060 URIBL_BLACK
> 829 URIBL_JP_SURBL
> 695 URIBL_OB_SURBL
> 611 URIBL_SC_SURBL
> 444 URIBL_SBLXBL
> 440 URIBL_WS_SURBL
> 427 URIBL_AB_SURBL
> 163 URIBL_RHS_DOB
> 42 URIBL_PH_SURBL
> 1329 Total Spam
>
> Spamhaus Zen is highly effective for me and hits on >90% of spam when
> used as -lastexternal, and is the only DNSRBL I'd trust to use at the
> smtp level. I've also added custom rules for UCE Protect levels 1-3 and
> PSBL blacklists. I wouldn't use either at the smtp level as they do
> generate the occasional FP, but UCE Protect is useful in a scoring
> environment such as SA. For me NJABL, SORBS and pretty much anything
> else are a waste of space relative to the effectiveness of Spamhaus. If
> you can implement Spamhaus Zen at the smtp level then blocking ~90% of
> spam before it ever reaches SA is hugely beneficial to system load and
> the rest could probably be dropped from SA with minimal impact.
>
> I also find the URIBLs to be very effective, especially URIBL_BLACK.
> Between Bayes and my top DNSRBLs and URIBLs, nothing gets through -
> everything else is just bumping the score further past the spam threshold.
>
> I'd recommend taking a look at your own stats to see which are effective
> for you and maybe drop those that are ineffective or, better still, look
> at ways to pre-filter spam at the smtp level before it ever reaches
> amavisd/SA so as to reduce the load (for example,
> http://wiki.centos.org/HowTos/postfix_restrictions). A good setup like
> this can easily block the vast majority of spam at the smtp level
> meaning that your server/SA now primarily only has to deal with the ham
> and an insignificantly small proportion of spam.
>
> BTW, checking my logs I note typical delays of 4-6secs on a 3.0GHz quad
> core server with 4GB RAM running 4 amavisd child processes that handles
> a very light load.
>
> -Ned
>
>
> Luis Croker
> SCSA - SCNA
> Administrador de Sistemas
> Megacable Comunicaciones
> GPG Key1024D/48C1764B
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